Cellular polyurethanes from organic isocyanates, high molecular weight polyether polyols and lower molecular weight hydroxy containing oxo bottoms



United States Patent CELLULAR POLYURETHANES FROM ORGANIC ISOCYANATES,HIGH MOLECULAR WEIGHT POLYETHER POLYOLS AND LOWER MOLECU- LAR WEIGHTHYDROXY CONTAINING OXO BOTTOM-S Joseph M. Lesser, Philadelphia, Pa.,assignor to Air Products and Chemicals, Inc., Philadelphia, Pa., acorporation of Delaware No Drawing. Filed May 27, 1963, Ser. No. 283,5849 Claims. (Cl. 2602.5)

The present invention relates to the preparation of urethane polymersand particularly to the utilization of certain relatively low molecularweight hydroxy compounds commonly characterized as 0X0 bottoms incombination with higher molecular Weight polyols in polyurethaneformulations.

It has been recognized heretofore that urethane polymers prepared by thereaction of polyols and isocyanates, usually in the presence of acatalyst, can be varied in physical properties by varying thefunctionality and molecular weight of the selected polyols and/ orisocyanates. In many instances a combination of polyols or a combinationof polyisocyanates has been used to obtain certain copolymerizedpolyurethanes. In the present instance a hydroxy material consisting ofa mixture of hydroxy compounds or potential hydroxy compounds, such asacetals and esters, carrying only the common terminology of OX0 bottoms,0X0 polymers or 0X0 residue is incorporated into urethane polymers alongwith higher molecular Weight polyols and diisocyanates to formdistinctive urethane polymers.

0X0 bottoms, polymer or residue, hereafter called 0X0 bottomsareproduced as byproducts in the 0X0 process which is directed primarily tothe conversion of olefins to primary alcohols. Olefinic hydrocarbonshaving the formula C H are reacted, generally in a two stage process,with (a) carbon monoxide and hydrogen in the presence of anorgano-cobalt catalyst at pressures of about 2000 to 4000 p.s.i. andtemperatures of about 275 to 375 F. to form principally an aldehydeproduct,

containing one more carbon atom olefin, which is then (b) furtherreacted with hydrogen in the presence of an active hydrogenationcatalyst at pressures of about 700 p.s.i. H and temperatures of about285-355 F. to reduce the aldehyde product to the corresponding alcohols,II 2 3 ()H:.

In current petrochemical processing of olefins to 0X0 alcohols narrowboiling range fractions of selected olefins are used rather than singleolefinic entities. Thus, when charging C to-C olefins to the process, Cto C alcohols than the precursor will be obtained, consisting ofisomeric primary alcohols depending upon the structure of the olefin,the position of the olefinic double bond in the molecule and thepositioning of the C0 in its addition to one of the two carbons of theolefinic double bond. y 4

The alcohol product as formed in the 0X0 process,

. however, is not solely alcoholic, but rather is a mixture 3,326,821Patented June 20, 1967 about- Percent by weight C .,C alcohols, averageC C C acetals, average C 19 0 -0 esters, average C 15 (F -C ethers,average C 17 Sp. gravity, 0845-0865. Acidity, 0l% (as HOAc). Hydroxylnumber, 160-260. Mol. weight, 265-275.

Such a bottoms fraction obtained principally as a byproduct of a largescale chemical process is available in large volume and at low cost. Inpresent day OX0 plant installations producing principally C to Calcohols and having a capacity of approximately 300,000,000 pounds of0X0 alcohols per year, about 6,000,000 gallons or about 50,000,000pounds of 0X0 bottoms are produced simultaneously.

Therefore, the principal object of the present invention is thepreparation of cellular urethane polymers utilizing substantialquantities of 0X0 bottoms in their formulation.

Another object of the present invention is the utilization ofsubstantial volumes of 0X0 bottoms in polyurethane formulations as apartial replacement for higher cost alcohols and polyols used heretoforein such formulations.

A further object of the present invention is the development ofpolyurethane formulations incorporating a selected amount of 0X0 bottomsas hydroxyl containing material which formulations are significantlysuperior in certain important characteristics to similar formulationswithout 0X0 bottoms.

Additional objects and advantages of the present invention will appearhereinafter.

In accordance with the present invention urethane polymers prepared bythe interaction of an organic compound having a plurality of isocyanategroups, a higher molecular Weight organic polyol and a lower molecularweight organic hydroxy compound, are improved by employing as the lowermolecular weight hydroxy compound a distillation bottoms fractionobtained in the distillation of 0X0 process product, which bottomfraction comprises from 5 to 15% of the total OX0 reaction product, andis present in the proportion of 1 to 35 parts by Weight per parts ofurethane formulation.

In one aspect of the invention, a species of rigid polyurethane foamshaving low heat conductivity and high dimensional stability on hot humidaging is prepared by reacting (a) from 1 to less than 10 parts by weightof a lower molal weight hydroxyl containing component characterized as0X0 bottoms,

(b) 30 to 40 parts by weight of a higher molal Weight polyol,

(c) 35 to 45 parts by Weight of a dior polyisocyante in the ratio of 1.0to 1.125 g. atoms of NCO per g. atom of 0H,

3 (d) 10 to 20 and preferably 13 to 16- parts by weight of a blowingagent, with (e) approximately 0.4 to 2 parts and preferably 1 part byweight of a foam stabilizer together with (f) 0.1 to 2.0 parts by weightof a metallo-organic soap and/ or a tertiary amine as catalyst;

effecting simultaneous polymerization and blowing with the production ofa rigid cellular urethane polymer having an initial coefiicient ofthermal conductivity no greater than 0.12, and a volume change on hothumid aging of less than 10%.

In another aspect of the present invention, cellular urethane polymershaving distinctive toughness and resiliency, as contrasted with rigidfoams, are prepared by reacting (a) from about 10 to 50 parts by weightof a generally lower molal weight hydroxy containing componentcharacterized as X0 bottoms together with (b) an equal or larger part ofhigher molal weight polyol and (c) a dior polyisocyanate in the ratio of1.0 to 1.25

g. atoms of isocyanate per g. atom of hydroxyl (d) blowing agent in 13to 16 parts by weight, with (e) approximately 1.0 part by weight of foamstabilizer together with (f) up to 2.0 parts by weight of anorgano-metallic soap and/or a tertiary amine as catalyst and etfectingsimultaneous polymerization and blowing.

The hydroxyl containing materials characterized as 0X0 bottoms are thedistillation residues obtained on distilling the mixed OX0 alcoholsproduced in the catalytic conversion of selected C to C olefinichydrocarbons as described above. While the composition of this mixtureis not fully known, it will be appreciated from the description givenabove that monofunctional, difunctional and I possibly even higherfunctional compounds are present which could react accordingly with thediisocyanates and polyisocyanates in the polyurethane formulation. Thus,aldehydes (acetals), ketones (ketals) and certain esters and ethersmight act difunctionally with diisocyanates in cross linking and chainextending reactions. On the other hand, simple monohydric components ofthe bottoms mixture would react with diisocyanates or polyisocyanates toform polymer grafts or side chains. It has been recognized that bygrafting organic groups on a linear polymer the physical properties ofthe polymer can be modified.

While 0X0 bottoms are preferred as the low cost hydroxyl containingresidual material for urethane polymer formation, compositions fromwhatever source consisting of higher alcohols, acetals, esters, ethers,and the like having substantially the composition of 0X0 bottoms can beused effectively in the process of the invention.

Polyurethane rigid foam formulations having outstanding dimensionalstability were prepared in which from 1 to up to 10 parts by weight ofthe total composition consisted of 0X0 bottoms. In small hand mixedbatches it was observed that these mixtures reacted well, generallygoing to a creamy state in less than 30 seconds and rising smoothly overa period of 30 to 180 seconds with the polymer surface in tack freecondition in 180 to 300 seconds or less. Cross sections of the cellularproduct in most cases showed evenly distributed fine cell structure with90% or more of closed cells and from 50 to 65 individual cells per inchof cross section.

EXAMPLE I A hand mixed Freon blown rigid foam was prepared employingtypical OX0 bottoms from the distillation of C C crude 0X0 alcohols as areplacement for part of the polyol prepolymer. The concentration of thelower molecular weight 0X0 bottoms was 7 parts by weight per 36 parts byweight of higher molecular weight polyether polyol (Atlas (32410), to 38parts by weight of crude T.D.I. (Nacconate 4040) (1.05 NCO/1.0 OH), 1.2parts by weight of silicone foam stabilizer (Carbide L520) 2 and 16parts by weight of Freon blowing agent (F11) with 0.4 part of dimethylethanol amine and 0.2 part of dibutyl tin dilaurate as catalystsdissolved in 1.2 parts of a higher polyol (OP3500). The mixture foamedin a normal manner, producing an evenly textured rigid foam with noapparent adverse effect due to the bottoms used. Tests on this productshowed:

Initial thermal cond. 0.12 B.t.u./hr./ F./ ft. in. Density 1.65 lb./ft.Compressive strength 25 lb./in.

The low thermal conductivity indicated that the closed cell nature oftypical rigid foams had not been altered by incorporating OX0 bottoms.Also the compressive strength was good, considering the low density ofthe foam prepared. All of the bottoms appeared to have been chemicallybound in the polymer, since there was no residual odor in the finishedrigid foam. It is noteworthy also that OX0 bottoms are fully compatiblewith the polyol, isocyanate, blowing agent and catalyst in the system,and, further, that the added OX0 bottoms reduce the viscosity of thepolyol, resulting in better mixing of ingredients and a more uniformlyfoamed product.

A number of additional hand mixed foams were made using higherconcentrations of 0X0 bottoms with commercially available polyols,organo-tin catalysts and diisocyanates. These products were recognizedas being distinctly tough and flexible.

EXAMPLE II 15.0 parts by weight of lower molal weight 0X0 bottoms weredissolved in 213 parts by weight of higher molal weight polyol 0.7 partby weight of silicone foam stabilizer,

1.2 parts by weight of dibutyl tin dilaurate, and

17.0 parts of Freon-type blowing agent, trifluorochloromethane.

To this mix was added 45.0 parts by weight of crude TDI.

on mixing, the formulation creamed readily, rose evenly for 2.12 minutesand was tack-free in 2.83 minutes.

The foamed product had risen to the full height of an 8.5 inch tub.After an oven cure of 1 hour at 250 F.

the product was a very smooth, even textured flexible foam, which showedno shrinkage on curing. The skin texture was particularly noted ashaving a resilient tough feel. In this formulation the 0X0 bottomsconstituted 15 wt. percent of the initial formulation, or 18.1 wt.percent of the blow finished product and 42 wt. percent of the totalhydroxyl component.

EXAMPLE III 1 Sorbitol-propylene oxide adduct, 2410 mol. wt., 490 OHnumber.

L520-a1ky1 silane polysiloxane polyoxyalkylene copolymer.

3 F11trifiuoro-chloro-methane.

CP3500-glycero1-pr0py1ene oxide adduct, 3500 mol. wt., 45 OH number.

5 G2566, a sorbitol, alkylene oxide polyether 600630 0H number.

'tensive and more rapid rigid foams. The formulati v erties in typicalmachine runs are shown in the following It was noted that when higherconcentrations 10%) of OX bottoms were used relative to the totalhydroxy component, the polymerized tack-free products tended to shrinkon storage and oven curing after storage. However this characteristicwas surprisingly overcome by immediately curing the polymerizedtack-free foam:

EXAMPLE IV 30 parts by weight of OX0 bottoms mixed with 100 parts byweight of polyol '(triol, CP3500, a polypropylene oxide adduct ofglycerine),

10 parts by weight of a Freon-type blowing agent and 4.8 parts ofactivator solution consisting of 0.2 part of diazabicyclooctane,

1.2 parts of silicone, L520 3.4 parts of water and 1 0.66 part ofdibutyl tin dilaurate in 1.32 parts of the above CP3500 as a solvent ina ratio of 1 part by 2 by weight respectively.

52 parts by weight of tolylene diisocyanate were added with stirring.

The mix foamed well, rising to its maximum height in 2.66 minutes. Theproduct was put in a 225-250" F. curing oven at once. In a one hour curethe flexible foamed product showed no shrinkage.

This improved result, whether caused by the more expolymerization andstabilization of the foam at curing temperature or by other meansinherent in the system, effectively demonstrates the utility of OX0bottoms at concentration levels above 10%. In Examples III and IV the0X0 bottoms constituted 20 as in Example I were and 15 wt. percentrespectively of the total urethane foam formulation and 48 and 23 wt.

I percent respectively of the total hydroxyl component.

' Larger volume one-shot machine runs were next made on theBayer-Hennecke foam machine using 0, and

by weight of OX0 bottoms in the formulationiThe foam formulationscontaining OXObot toms behaved normally on the machine, producing wellblown, evenly cellular foaming and product propexamples:

EXAMPLES Parts by wt. V VI VII 0X0 bottoms. 0 5 10 Polyol, G24l0 41. 338. 5 34. Freon-F11 l 13. 4 14. 9 15. Silicone, L520. 0. 7 0. 7 0.Nacconate 4040. 43 39. 4 37. Catalyst:

0. 4 0.4 0. 0. 2 '0. 2 0'. 0. 6 1. 2 1. 1. 125 1. 064 1. 07 Rise time,sec 30 a 52 40 Physical Tests onProducts:

Density, lb./ft. i 2.1 1. 95 2.65 Closed cells, percent 95 95 91 Thermalk, initial 0.124 0.115 0.117 Thermal k at 14 dll40 F./dry. 0.15 0.160.18 Dimensional Stability:

Percent change after 24 hrs. at

20 F +0.4 0. 2 +2 3 Percent change after 7 days at 15 F., 100% Humidity+30 to +45 +1. 6 +6. 0

*Polyol G2410-S0rbitol-propylene oxide addnct, hydroxyl 490.

Freon-F11Trichlorofiuoro-methane.

Silicone L-520-Water soluble alkyl silane polysiloxane, polyoxyalkylenecopolyrners.

Nacconate 4040-Mixed crude diisocyanates, principally tolylenediisocyanate.

DBTDL-Dibutyl tin dilaurate.

DMEA-Dimethy] ethanolamine.

Voranol CP3500-Propylene oxide adduct of glycerol, 3,500 mol. wt. 45 OHnumber.

For the production of rigid cellular polyurethanes having low density,low thermal conductivity, and excellent dimensional stability, from 1%to up to 10% by weight of 0X0 bottoms can be incorporated to advantage.At a preferred concentration of about 5% by weight, 0X0 bottomscontribute distinctly beneficial effects to the rigid cellular product.The coefficient of thermal conductivity is unexpectedly as low as orlower for the OX0- containing products than for the non-0XO formulatedproduct. In view of the major use of rigid polyurethane foams in thermalinsulation applications, the replacement of conventional polyols withOX0 bottoms contributes a significant economic advantage to the foamscontaining OX0 bottoms in view of the substantially lower cost of OX0bottoms than that of conventional polyols.

The most striking result of incorporating OX0 bottoms in rigid foams wasobserved when rigid foam samples were submitted to aging tests underconditions of moderately high temperature (158 F.) and humidity (100%).Although the control sample swelled as much as 30 to 45%, the foamsample containing 5% of OX0 bottoms swelled only 2 to 3% and the foamedproduct containing up to 10% of OX0 bottoms showed considerably lessthan 10% distortion. Dimensional stability is of extreme importance incommercial applications of rigid foams, as for example, in foamed inplace rigid foams to build up internal stabilityof aircraft propellers,wings and airframe sections. Thus a standard rigid foam made withconventional polyols would swell from 10 to 15 times as much as thecorresponding product made with 5% of 0X0 bottoms. With thepreponderance of rigid foam uses concentrated in the field of structuralmaterials and interwall insulation, these properties of low thermalconductivity and high dimensional stability are of extreme significance.

From the above examples the use of OX0 bottoms in polyurethanes fallsinto two categories. With from 1 up to 10%, preferably from 3 to 7%, of0X0 bottoms in the formulation, rigid foams can be produced havingexcellent insulating properties and exceptional dimensional stability,while with from'above 10% to about 35%, preferably 15 to 25% of OX0bottoms in the formulation, cellular polyurethanes are formed having atough but flexible structure. Since each of these products has distinctcommercial applications, both variants are within the general concept ofthe invention.

Whereas, in the foregoing description the OX0 alcohols and bottoms areprimarily the products of the OX0 process utilizing C to C olefins orclosely related olefinic cuts which may include C to C olefins, the 0X0process in general is applicable to carbonylation and hydrogenation oflower and higher molal weight olefins with the resultant production of abroader range of alcohols and bottoms. Olefins as low as ethylene andpropylene have been oxonated successfully to the corresponding propanoland butanols. The yield of desired butanols was about with about 15 ofthe product appearing as higher boiling bottoms. Olefins even above Chave been oxonated to C 1 and higherwaxalcohols, which were outstandingemulsifiers. Thus, the bottoms product from the OX0 process may cover aconsiderable range of alcohols, acetals, aldehydes, esters, ethers, etc.which accompany the formation of the OXO alcohols. With similarfunctional groups as in the bottoms from C C alcohols, their reactivitywith isocyanates in urethane formation will be similar to the bottomsproduct described above, but not identical in their eifect in view oftheir lower or higher molecular weight and the correspondingly greateror lesser reactivity per unit weight of bottoms.

Similarly, combinations consisting of higher molecular weight alcohols,aldehydes, acetals, esters and ethers having substantially thecomposition of 0X0 bottoms, whether composited from separate componentsor obtained as a product mixture will react in the manner shown above inthe formation of polyurethanes of unusual character.

Obviously, many modifications and variations of the invention ashereinbefore set forth may be made without departing from the spirit andscope thereof, and therefore only such limitations should be imposed asare indicated in the appended claims.

What is claimed is:

1. In the method of preparing cellular urethane polymers by theinteraction of an organic polyisocyanate with both a polyether polyolhaving a molecular weight of about 2410 to about 3500 and a lowermolecular weight hydroxy material, the improvement obtained by employingOXO bottoms as said lower molecular weight hydroxy material, said OXbottoms having a molecular weight of about 265 to about 275, hydroxylvalue of about 160 to about 260 and being a distillation residuecontaining a mixture of primarily mono-functional organic compoundsconsisting essentially of alcohols, esters, ethers and acetals which isobtained by the (a) oxonation of C to C olefinic hydrocarbons withcarbon monoxide and hydrogen in the presence of a cobalt catalyst toform aldehydes containing one more carbon atom than the precursorolefin, (b) reduction of the oxonation product with hydrogen and anactive hydrogenation catalyst and (c) distillation of the reducedreaction product, said bottoms used in the proportion of from 1 part to35 parts by weight per 100 parts of total formulation.

2. The method of claim 1, wherein said OX0 bottoms are present in theproportion of from 1 to less than parts by weight per 100 parts of totalformulation.

3. The method of claim 1, wherein said 0X0 bottoms are present in theproportion of about to 35 parts by weight per 100 parts of totalformulation.

4. The method as in claim 3 wherein the cellular polymer, uponattainment of maximum foam height, is subjected to a temperature ofabout 225 to about 250 F. to effect curing of the polymer product. p

5. The method of preparing rigid polyurethane foams which consistsessentially in reacting (a) a polyether polyol having a molecular weightof about 2410 to about 3500; (b) 1 to about 10 parts by weight per 100parts of total formulation of OX0 bottoms, said OX0 bottoms having amolecular weight of about 265 to about 275, a hydroxyl value of about160 to about 260 and being a distillation residue containing a mixtureof primarily mono-functional organic compounds consisting essentially ofalcohols, esters, ethers and acetals which is obtained by the (1)oxonation of C to C olefinic hydrocarbons with carbon monoxide andhydrogen in the presence of cobalt catalyst to form aldehydes containingone more carbon atom than the precursor olefin, (2) reduction of theoxonation product with hydrogen and an active hydrogenation catalyst and(3) distillation of the reduced reaction product; (c) an organicdiisocyanate in the ratio of 1.0 to 1.125 gram atoms of isocyanate pergram atom of hydroxyl; (d) a blowing agent; (e) a foam stabilizer and(f) .a catalyst; and effecting simultaneous polymerization and blowing.

6. The method of claim 5 wherein OX0 bottoms are present in the ratio ofabout 3 to 7 parts by weight per parts of total formulation.

7. The method of preparing resilient cellular polyurethane foams whichconsists essentially in reacting (a) a polyether polyol having amolecular weight of about 2410 to about 3500 (b) about 10 to 35 parts byweight per 100 parts of total formulation of OX0 bottoms, said OX0bottoms having a molecular weight of about 265 to about 275, a hydroxylvalue of about to about 260 and being a distillation residue contaning amixture of primarily mono-functional organic'compounds consistingessentially of alcohols, esters, ethers and acetals which is obtained bythe (1) oxonation of C to C olefinic hydrocarbons with carbon monoxideand hydrogen in the presence of a cobalt catalyst to form aldehydescontaining one or more carbon atoms than the precursor olefin, (2)reduction of the oxonation product with hydrogen and an activehydrogenation catalyst and (3) distillation of the reduced reactionproduct; (c) an organic diisocyanate; (d) .a blowing agent; (e) a foamstabilizer and (f) a catalyst; and effecting simultaneous polymerizationand blowing.

8. The method of claim 7 wherein 0X0 bottoms are present in a ratio ofabout 15 to 25 parts by weight per 100 parts of total formulation.

9. Polyurethane foam prepared by reacting from 1 to 35 parts by weightof OX0 bottoms, said 0X0 bottoms having a molecular weight of about 265to about 275, a hydroxyl value of about 160 to about 260 and being adistillation residue containing a mixture of primarily monofunctionalorganic compounds consisting essentially of alcohols, esters, ethers andacetals which is obtained by the (a) oxonation of C to C olefinichydrocarbons with carbon monoxide and hydrogen in the presence of acobalt catalyst to form aldehydes containing one more carbon atom thanthe precursor olefin, (b) reduction of the oxonation product withhydrogen and an active hydrogenation catalyst and (c) distillation ofthe reduced reaction product; a polyether polyol having a molecularweight of about 2410 to about 35 00; a blowing agent; a foam stabilizer;and a catalyst selected from the group consisting of metal-soaps andtertiary amine, together with an active organic diisocyanate in theratio of 1.0 to 1.125 gram atoms of isocyanate per gram atom ofhydroxyl.

References Cited UNITED STATES PATENTS 2,801,971 8/ 1957 Bartlett et a1260-604 2,839,478 6/ 1958 Wilms et al. 260-2.5 2,842,514 7/ 1958Bartlett et a1 260-604 2,945,050 7/1960 Franke et a1 260-604 3,202,6208/1965 Morten et a1. 260--2.5

DONALD E. CZAJA, Primary \Examiner.

LEON J. BERCOVITZ, I. I. KLOCKO,

Assistant Examiners.

1. IN THE METHOD OF PREPARING CELLULAR URETHANE POLYMERS BY THEINTERACTION OF AN ORGANIC POLYISOCYANATE WITH BOTH A POLYETHER POLYOLHAVING A MOLECULAR WEIGHT OF ABOUT 2410 TO ABOUT 3500 AND A LOWERMOLECULAR WEIGHT HYDROXY MATERIAL, THE IMPROVEMENT OBTAINED BY EMPLOYINGOXO BOTTOMS AS SAID LOWER MOLECULAR WEIGHT HYDROXY MATERIAL, SAID OXOBOTTOMS HAVING A MOLECULAR WEIGHT OF ABOUT 260 AND BEING A DISTILLATIONRESIDUE CONTAINING A MIXTURE OF PRIMARILY MONO-FUNCTIONAL ORGANICCOMPOUNDS CONSISTING ESSENTIALLY OF ALCOHOLS, ESTERS, ETHERS AND ACETALSWHICH IS OBTAINED BY THE (A) OXONATION OF C6 TO C12 OLEFINICHYDROCARBONS WITH CARBON MONOXIDE AND HYDROGEN IN THE PRESENCE OF ACOBALT CATALYST TO FORM ALDEHYDES CONTAINING ONE MORE CARBON ATOM THANTHE PRECURSOR OLEFIN, (B) REDUCTION OF THE OXONATION PRODUCT WITHHYDROGEN AND AN ACTIVE HYDROGENATION CATALYST AND (C) DISTILLATION OFTHE REDUCED REACTION PRODUCT, SAID BOTTOMS USED IN THE PROPORTION OFFROM 1 PART TO 35 PARTS BY WEIGHT PER 100 PARTS OF TOTAL FORMULATION.